Turn on the first for one min and then turn it off./ O; ]" W+ r$ s' I# k) G4 D4 w# n
Turn on the 2nd for five min and then turn it off. ; Q) O0 ] t1 ?( cTurn on the 3rd and leave it on. - o, u% H* e; zAnd then go upstairs right away. * p r$ C7 g0 _/ p! X( v+ c5 L. \1 J
Find the answer by using your fingers and eyes5 p) p( j8 ]0 C9 b, W( m8 Q% d
这只是一个智力问题,不象是电工问题。
原帖由 老警察 于 2009-1-16 07:12 发表 ; [* f5 p! P. X
Turn on the first for one min and then turn it off. 1 V: g5 _- t. O, [; Y6 x3 E6 K, T8 zTurn on the 2nd for five min and then turn it off.; C' u3 _6 ~' `
Turn on the 3rd and leave it on.$ B( A$ E# c! Q6 h ?! U# p/ w
And then go upstairs right away.' k& E4 U; Y; e8 k5 B* t# D
( p& c4 d; C7 _( N$ c! H5 |& gFind the answer by using ...